Data Encryption Standard (DES)
A National Institute of Standards and Technology (NIST) standard secret key cryptography method that uses a 56-bit key encryption. DES is based on an IBM algorithm, which was further developed by the U.S. National Security Agency. It uses the block cipher method, which breaks the text into 64-bit blocks before encrypting them. There are several DES encryption modes. The most popular mode exclusive ORs each plaintext block with the previous encrypted block. DES decryption is very fast and widely used. The secret key may be kept completely secret and reused again, or a key can be randomly generated for each session, in which case, the new key is
transmitted to the recipient using a public key cryptography method such as RSA. Triple DES (3DES) is an enhancement of DES that provides
considerably more security than standard DES, which uses only one 56-bit key. There are several 3DES methods. EEE3 uses three keys and encrypts three times. EDE3 uses three keys to encrypt, decrypt, and encrypt again. EEE2 and EDE2 are similar to EEE3 and EDE3, except that only two keys are used, and the first and third operations use the same key.
Dynamic Host Control Protocol (DHCP)
The protocol used to assign Internet Protocol (IP) addresses to all nodes on the network.
Hash Function A computationally efficient algorithm that maps a variable-sized amount of text into a fixed-sized output (hash value). Hash functions are used in creating digital signatures.
Industrial, Scientific, and Medical (ISM) Band
The ISM band refers to the government-allotted bandwidth at 2.450 ± .050 gigahertz (GHz) and 5.8 ± 0.75 GHz.
Infrared (IR) An invisible band of radiation at the lower end of the electromagnetic spectrum. It starts at the middle of the microwave spectrum and extends to the beginning of visible light. Infrared transmission requires an
unobstructed line of sight between transmitter and receiver. It is used for wireless transmission between computer devices, as well as for most handheld remotes for TVs, video, and stereo equipment.
Institute of Electrical and Electronics Engineers (IEEE)
A worldwide professional association for electrical and electronics engineers that sets standards for telecommunications and computing applications.
International Electrotechnical Commission (IEC)
An organization that sets international standards for the electrical and electronics fields.
International Organization for Standardization (ISO)
A voluntary organization responsible for creating international standards in many areas, including computers and communications.
Jini An approach to instant recognition that would enable manufacturers to make devices that can attach to a network independently of an operating system. Jini can be viewed as the next step after the Java programming language toward making a network look like one large computer. Each pluggable device in a network will define itself immediately to a network device registry. Using the Jini architecture, users will be able to plug printers, storage devices, speakers, and any other kind of device directly into a network, and every other computer, device, and user on the network will know that the new device has been added and is available through the network registry. When a user wants to use or access the resource, their computer will be able to download the necessary programming from it to communicate with it. In this way, devices on the network may be able to access and use other devices without having the drivers or other previous knowledge of the device.
Local Area Network (LAN)
A network that connects computers in close proximity via cable, usually in the same building.
Medium Access Control (MAC)
On a local area network, the sublayers that control which device has access to the transmission medium at a particular time.
Open Systems Interconnection (OSI)
A model developed by ISO to allow computer systems made by different vendors to communicate with each other.
Personal Digital Assistant (PDA)
A handheld computer that serves as an organizer for personal information. It generally includes at least a name-and-address database, a to-do list, and a note taker. PDAs are pen-based and use a stylus to tap selections on menus and to enter printed characters. The unit may also include a small on-screen keyboard that is tapped with the pen. Data is synchronized between a user’s PDA and desktop computer by cable or wireless transmission.
Request for Comments (RFC)
A series of numbered documents (RFC 822, RFC 1123, etc.), developed by the Internet Engineering Task Force (IETF) that set standards and are voluntarily followed by many makers of software in the Internet community.
Smart Card A credit card with a built-in microprocessor and memory that is used for identification or financial transactions. When inserted into a reader, the card transfers data to and from a central computer. A smart card is more secure than a magnetic stripe card and can be programmed to self-destruct if the wrong password is entered too many times.
Spoofing IP spoofing refers to sending a network packet that appears to come from a source other than its actual source.
Virtual Private Network (VPN)
A means by which certain authorized individuals (such as remote
employees) can gain secure access to an organization's intranet by means of an extranet (a part of the internal network that is accessible via the Internet).
Wireless Application Protocol (WAP)
A standard for providing cellular telephones, pagers, and other handheld devices with secure access to e-mail and text-based web pages. Introduced in 1997 by Phone.com, Ericsson, Motorola, and Nokia, WAP provides a complete environment for wireless applications that includes a wireless counterpart of TCP/IP and a framework for telephony integration, such as call control and telephone book access. WAP features the Wireless Markup Language (WML), which was derived from Phone.com’s HDML and is a streamlined version of HTML for small-screen displays. It also uses WMLScript, a compact JavaScript-like language that runs in limited memory. WAP also supports handheld input methods, such as a keypad and voice recognition. Independent of the air interface, WAP runs over all the major wireless networks in place now and in the future. It is also device- independent, requiring only a minimum functionality in the unit to permit use with a myriad of telephones and handheld devices.